1. Statement of the Technical Field
The present invention relates to the field of user interface rendering and more particular to the cross-platform rendering of content in variable presentation environments.
2. Description of the Related Art
Modern network-deployed client-server systems involve the generation and transmission of data requests over a network from clients to servers, and the resulting generation and transmission of a data responses to the requesting clients. In many cases, the servers can format data responses for presentation in particular clients. For instance, in the case of a Web application, a Web server can format requested data using the hypertext markup language (HTML) for presentation in a Web browser.
Recently, the extensible markup language (XML) has become a popular means for describing network distributable content. In particular, XML enjoys a flexibility in describing network distributable content which heretofore has been lacking in other markup languages like HTML. In consequence of the development and resulting widespread use of XML, presentation tools also have been developed for facilitating the reading and formatting of XML-formatted data for presentation in client browsers. Notwithstanding, to support older client environments which may include a diverse set of browsers for operation in a multiplicity of different operating systems and hardware platforms, it is necessary to avoid the use of newer tools if portability is an important goal.
For example, the same set of data produced by a server and formatted using XML may be presented at any time in each of a stand-alone executable client, a conventional desktop Web browser, and a microbrowser in a handheld device such as a cellular phone or personal digital assistant. Notably, each platform presents formatted data in different ways. Even in regard to the presentation of data in a conventional desktop Web browser, incompatibilities between browser versions further complicate the task at hand.
International Business Machines Corporation (IBM) has developed a solution which particularly addresses the problem of rendering XML-formatted data in one of a bevy of differing content browsers. This solution is described in substantial detail in U.S. Pat. No. 6,012,098 to Bayeh et al. (Bayeh). In the IBM solution, a system is described in which a content server isolates the retrieval of data from the rendering of the data into a presentation format. More particularly, data retrieval logic is isolated to a data servlet, while presentation formatting logic is isolated to a rendering servlet.
Still, the IBM solution described in Bayeh relies heavily upon the use of style sheets, for example style sheets formatted in accordance with the extensible style language (XSL) or the cascading style sheet (CSS). Importantly, style sheets typically require the use of corresponding style sheet parsers. Yet, as one skilled in the art will recognize, style sheets based upon XSL and CSS technology are not always an appropriate solution where computing resources are not abundant. In particular, computing resources are limited in those cases where “thin renderers” are utilized, for example in a microbrowser. Like other thin renderers, microbrowsers can support conventional HTML, but typically not style sheets. Thus, in the cases where content is to be distributed not only to robust desktop-based content browsers, but also to thin content browsers, a more flexible, resource efficient method is appropriate.